Implement accidental paste protection about circe

[retroj]

I think this only affects terminal users, where pasting a newline character causes the line to be sent. In gui emacs, pasting a newline at the prompt does not cause the text to be sent, so if paste protection is desired for the gui, it would take a different form, such as testing the length of the input and prompting for confirmation.

[jorgenschaefer]

Fascinating. I didn't know the GUI version fixes that.

That means this is only useful for (not (window-system)) frames. Possibly as an external mode so it doesn't clutter up circe.el, depending on how big the change would be.

[jorgenschaefer]

I've been playing with test implementations of this a bit. This is a tricky beast.

To do "perfect" paste protection, Circe has to delay sending any PRIVMSG to the server, just in case it is followed up with another few. This delay is noticeable, even at lengths of 0.2s. Below that, it does not work because Emacs needs longer than that to actually process the input for long lines.

Not-so-perfect paste protection could send the first few lines and then kick in. The best place for this I found would be in lui-send-input.

[jorgenschaefer]

I do not see a sensible way to do paste protection for terminals here. Annoying. Begone, ticket.